So basiclly,

Henry was getting mad at him for the way he was "coping" with cc's death, so he was like "Lets f-ing see how you react when your f-ing child dies" and so he killed her.

Not a very good reason, but then again hes not a very sane person so...

He killed her for remnant

Um killed her cuz he sees random child and is like ‘Oh my god can’t she just stop crying?’ And so he sees it be Charlie and is all like ‘oh it’s you’ and she cries harder and he gets peed off and kill her, mostly cuz he can. He be serial killer, he murder my bean JEREMY TvT I don’t really care what reason is he is bad bad bad man

Bad man.

YOU HEAR THAT WILLIAM? YEAH I AINT SCARED OF YOU IVE GOT ALL OF YOUR F-ING KIDS ON MY SIDE.